ECHO ERASING DEVICE

摘要

PURPOSE:To effectively cancel an echo signal by assuming the reverberation time of an echo path with an initial training signal and variably setting a tap length in order to generate a pseudo echo signal in accordance with the reververating time. CONSTITUTION:A learning circuit 4 inputs the initial training signal outputted from a training circuit 3 and assumes the echo path characteristics of the echo path formed by an acoustical coupling between a speaker 1 and a microphone 2 in the form of an impulse response. A coefficient multiplier 6 multiplies each tap output of a tap delay line 5 by a tap coefficient, which constitutes the echo characteristics assumed at the learning circuit 4, and executes tap- coefficient-processing. An adder 7 adds each tap-coefficient-processed tap output and generates the pseudo echo signal. The pseudo echo signal is given to a subtracter 8 and the cancellation of the echo signal contained in an input sound signal is executed.